There are typically three main phases that are undertaken to obtain hydrocarbons from a given field of development or on a per well basis. The phases are exploration, appraisal and production. During exploration one or more subterranean volumes (i.e., reservoirs) are identified that may include fluids in an economic quantity.
Following successful exploration, the appraisal phase is conducted. During the appraisal phase, operations, such as drilling wells, are performed to determine the size of the oil or gas field and how to develop the oil or gas field. After the appraisal phase is complete, the production phase is initiated. During the production phase fluids are produced from the oil or gas field.
More specifically, the production phase involves producing fluids from a reservoir. A wellbore is created by a drilling operation, and the wellbore perforates the reservoir. Once the drilling operation is complete and the wellbore is formed, completion equipment is installed in the wellbore, which is reinforced with a casing for purposes of production. The casing is perforated at a depth corresponding with the reservoir, and the fluids in the reservoir are allowed to flow from the reservoir to surface production facilities. At the end of the drilling operation, an analysis is conducted to determine the potential to produce hydrocarbons from the reservoir. One factor in determining the potential to produce hydrocarbons from a reservoir is permeability.
In various parts of the world, the swabbing test is the conventional technique used by companies to induce fluid to flow from the reservoir into the wellbore in reservoirs in which this does not naturally occur. When swabbing tests are used in a wellbore, conventional methods for analyzing pressure measurements taken in the wellbore, including but not limited to semilog slope, log-log horizontal line, convolution algorithms, and conventional transient pressure analysis, may not be used because the fluid flow rate over the duration of the swabbing test is not constant.